What version of the Nvidia Shield?
Dolphin is not optimized for mobile devices (smartphones, tablets and the like), and using them with the emulator is suggested only for devs and/or testers. Don't expect to be able to play Wii or Gamecube games on any tablet. The latest Shield uses an Nvidia Tegra quad-core mobile processor and has 2GB of memory. Nvidia processors with their ARM chipset is incapable of emulating GC/Wii ATM. Mobile devices will likely be able to use Dolphin in the next few years.